Solar Modulation Model Research Articles

Modeling and manufacturing of solar modules of different designs for energy supply of biogas plant

The article presents a description of the modeling and manufacturing of solar modules of photovoltaic, thermal and photovoltaic thermal designs intended to supply energy to a biogas plant intended for the production of biohydrogen and biomethane. Mathematical modeling of the photovoltaic module was carried out and the calculated temperature of the photovoltaic converters was determined, and also the photovoltaic module was manufactured using the process of sealing the photovoltaic converters with a two-component polysiloxane compound. Mathematical modeling of a solar thermal collector with water radiators in the form of a round copper tube, an oval copper tube, as well as a rectangular water cooling channel (“water jacket”) was also carried out, in which pressure losses and the amount of water heating were assessed. The distances between the rectangular channels of the water-cooling radiator for uniform heat removal were determined, and mathematical modeling of the thermal state of a solar thermal collector with a semicircular cross-section of the water-cooling radiator channel was carried out, after which the solar thermal collector was manufactured. Mathematical modeling of the total displacements of the components of a photovoltaic thermal module, the values of which do not exceed acceptable limits, was carried out, after which a photovoltaic thermal module was manufactured using the process of sealing photovoltaic converters with a two-component polysiloxane compound.

A New Scenario of Solar Modulation Model during the Polarity Reversing

When entering the heliosphere, galactic cosmic rays (GCRs) will encounter the solar wind plasma, reducing their intensity. This solar modulation effect is strongly affected by the structure of the solar wind and the heliospheric magnetic field (HMF). To address the effect during the solar maximum of cycle 24, we study the solar modulation under a scenario in which the weights for A = ±1 are determined by the structure of HMF, and the traveling time of GCRs simulated by SOLARPROP is taken into account. We then fit the cosmic-ray proton data provided by AMS-02 and Voyager in the energy range 4 MeV–30 GeV, and confirm that the modulation time lag in this model is about 9 months, which is consistent with the previous studies. This model incorporates a more realistic description of the polarity reversing and provides a more reliable estimation of the solar modulation effect during the maximum activity period.

An Improved Flower Pollination Algorithm based Modelling Method of Photovoltaic Modules

In recent years, with the acceleration of the global carbon emission reduction process, the sustainable development of clean energy has become the leading role, and the photovoltaic (PV) market has ushered in a hotter market. For accurately estimating the power generation of PV modules under different weather conditions, the modeling of solar cells or PV modules is very important. However, the conventional optimization algorithms cannot satisfy the accuracy of identification of the five parameters in the single diode model. In this paper, an improved FPA is proposed to estimate the five model parameters of the PV modules. In the proposed algorithm, the FPA is improved by considering different updating methods of solution for each pollen, with or without Levy flight. Experimental results validate that the proposed improved FPA can accurately identify the five model parameters and satisfy the modeling demands of PV arrays in engineering applications.

Current status and new perspectives on cosmic ray deuterons

Deuterons are the most abundant secondary cosmic ray species in the Galaxy, but their study has been severely limited due to experimental challenges. In an era with new experiments and high-precision measurements in cosmic rays, having a low-uncertainty deuteron flux in a wide energy range becomes possible. The deuteron-over-helium ratio ($d/^{4}\mathrm{He}$) is important to understand the propagation of cosmic rays in the Galaxy and in the heliosphere, complementing observations with heavier nuclei like the boron-to-carbon ratio. In this work, the most up-to-date results of the deuteron flux and the $d/^{4}\mathrm{He}$ ratio at the top of the atmosphere have been obtained using galprop and a 3D solar modulation model. It was found that the simulation describes the deuteron flux and $d/^{4}\mathrm{He}$ data below $1\text{ }\text{ }\mathrm{GeV}/n$ within the uncertainties of the model. However, the model underestimates the best-published measurements available at high energy. This discrepancy suggests different effective diffusions have to be considered between secondary light species like deuterons and heavier nuclei. Either this is a consequence of a break in the universality of propagation between light and heavier nuclei or a lack of precision measurements, it is something AMS-02 will help to resolve in the near future.

Astronaut Radiation Dose Calculation With a New Galactic Cosmic Ray Model and the AMS‐02 Data

AbstractWe present a new calculation of the astronaut dose rate from the galactic cosmic rays in free space at 1 AU. We use the unshielded isotropic fluence‐to‐dose conversion coefficients given in the International Commission on Radiological Protection publication 123. A new 3D and time‐dependent solar modulation model based on Parker's transport equation as originally developed in Song et al. (2021, https://doi.org/10.3847/1538-4365/ac281c) is used to calculate the galactic cosmic ray spectra at 1 AU. This model uses the recent local interstellar spectra of Corti et al. (2019, https://doi.org/10.3847/1538-4357/aafac4), M. J. Boschini et al. (2020, https://doi.org/10.3847/1538-4365/aba901, 2021a, https://doi.org/10.3847/1538-4357/abf11c) to reproduce the PAMELA and AMS‐02 observations between 2006 and 2019. The radiation dose calculated from our model and from the AMS‐02 spectra in the same rigidity region agrees better than 1% for proton and helium in a time‐dependent way, and at 2% level for six most contributing cosmic ray elements averaged over 7 or 8.5 years. The time‐dependent dose rate analysis over 13 years shows an effective dose equivalent rate of 55–58 cSv/yr at solar minimum (January 2010) and 26 cSv/yr at solar maximum (February 2014).

Explaining the GeV Antiproton Excess, GeV γ -Ray Excess, and W -Boson Mass Anomaly in an Inert Two Higgs Doublet Model

For the newly discovered W-boson mass anomaly, one of the simplest dark matter (DM) models that can account for the anomaly without violating other astrophysical and experimental constraints is the inert two Higgs doublet model, in which the DM mass (m_{S}) is found to be within ∼54-74 GeV. In this model, the annihilation of DM via SS→bb[over ¯] and SS→WW^{*} would produce antiprotons and gamma rays, and may account for the excesses identified previously in both particles. Motivated by this, we reanalyze the AMS-02 antiproton and Fermi-LAT Galactic center γ-ray data. For the antiproton analysis, the novel treatment is the inclusion of the charge-sign-dependent three-dimensional solar modulation model as constrained by the time-dependent proton data. We find that the excess of antiprotons is more distinct than previous results based on the force-field solar modulation model. The interpretation of this excess as the annihilation of SS→WW^{*} (SS→bb[over ¯]) requires a DM mass of ∼40-80 (40-60)GeV and a velocity-averaged cross section of O(10^{-26}) cm^{3} s^{-1}. As for the γ-ray data analysis, besides adopting the widely used spatial template fitting, we employ an orthogonal approach with a data-driven spectral template analysis. The fitting to the GeV γ-ray excess yields DM model parameters overlapped with those to fit the antiproton excess via the WW^{*} channel. The consistency of the DM particle properties required to account for the W-boson mass anomaly, the GeV antiproton excess, and the GeV γ-ray excess suggests a common origin of them.

Solar modulation of cosmic proton and helium with AMS-02

We investigate the solar modulation effect with the long-time cosmic ray (CR) proton and helium spectra measured by AMS-02 on the timescale of a Bartels rotation (27 days) between May 2011 and May 2017. The time covers the negative heliospheric magnetic field polarity cycle, the polarity reversal period, and the positive polarity cycle. The precise AMS-02 data provide an excellent opportunity to improve the understanding of the time-dependent solar modulation effect. In this work, a two-dimensional solar modulation model is used to compute the propagation of cosmic rays in the heliosphere. The CR propagation equation is numerically solved by the public code solarprop. We find that the drift effect is suppressed during the high solar activity period for a long time but nearly recovered in the first half of 2017. The time-dependent rigidity dependence of the mean free path is critical to reproduce the observations during the polarity reversal period. We also confirm that protons and helium have the same diffusive mean free path. The future monthly AMS-02 and PAMELA data will further confirm the vital assumption about the universal mean free path for all species. The monthly antiproton data will be crucial to break the degeneracy between the diffusion and drift effect and determine the level of drift effect during different epochs.

Mathematical Modeling Application in Energy Conversion and Energy Storage

The use of mathematical modeling to predict and investigate the effect of process variables in the research and engineering field of energy conversion and energy storage has also received special attention from scientists and industrial designers in this field due to their importance in the global economy. This review article investigates the applications of mathematical modeling and simulation in energy conversion and energy storage processes, and finally, with a case study, the application of mathematical modeling in the desired processes to be tested and compared with the reported results in the papers. In the first part, the main emphasis is on energy conversion, especially on the structure of solar cells and fuel cells and mathematical modeling methods, and predicting the effect of operating variables on their performance. The basic principles of modeling solar cells and fuel cells to understand the relationships governing the current, voltage, performance, and power of PV modules are to be discussed. And with a case study, modeling of the process to estimate the performance of PV modules and SOFC in various conditions has been investigated. In the second part, the main focus is on the mathematical modeling of energy storage devices including batteries and supercapacitors. Supercapacitors and batteries are electrochemical energy storage devices that can be charged within a few seconds to a few minutes. This efficient energy storage is based on the electrocatalytic effect of the electrode with a high surface area. The mathematical equations governing the battery and supercapacitor are discussed in the article, and battery and supercapacitor performance are to be simulated as a case study. Due to the Multiphysics nature of energy conversion and storage systems, the simulation is performed in two stages. In the first step, the semiconductor equations are applied and the electrical response of the electrochemical device is modeled. In the second step, if needed, the thermal equations can be entered into the main calculations and the net amount of heat and the temperature profile in the desired device is evaluated. The main goals and ideas of compiling this review article are expressing the importance and role of electrochemical and electrocatalysts in energy production and storage processes and paying attention to the governing mechanism and mathematical equations and highlighting important and common models used in different parts of energy conversion and storage in a coherent article.

Temperature-Dependent Optical Modeling of Perovskite Solar Cells

Comprehensive temperature-dependent optical modeling of perovskite solar cells (PSCs) and modules is essential to accurately predict their energy yield and quantify their energy losses under real-world operating conditions, where devices are subject to different irradiance spectra and intensities as well as operating temperatures. These models require the accurate determination of the temperature-dependent optical constants of perovskites. Here, we report on these data, empirically determined via spectroscopic ellipsometry, for triple-cation perovskites with band gaps ranging between 1.58 and 1.77 eV at temperatures between 25 and 75 °C. Using this data set, we develop a simple empirical model to obtain the temperature-dependent optical constants of perovskites of an arbitrary band gap. We validate our empirical model by comparing the measured temperature-dependent short-circuit current densities and external quantum efficiency data of single-junction PSCs with simulated results using the modeled optical constants.

The transport of galactic cosmic rays in heliosphere: The HelMod model compared with other commonly employed solar modulation models

HelMod model allows one to describe how solar modulation affects the propagation of galactic cosmic rays (GCRs) through the heliosphere by solving the Parker transport equation. HelMod provides modulated spectra for protons and nuclei during high and low solar activity periods, in the inner and outer heliosphere, at Earth location and outside the ecliptic plane, as well as at different distances from Sun in the inner and outer heliosphere. The GCRs mainly constitute the high-energy population of the so-called space radiation environment. Modulated cosmic-ray spectra of protons and nuclei, obtained from HelMod and other solar modulation codes were compared to the AMS–02 spectra ranging from GeV up to TeV energies. Concerning other commonly used solar modulation models, HelMod modulated spectra are available over the entire rigidity range and observation period of AMS–02 mission. A quantitative comparison among models was carried out using ΔΦ, i.e., the relative difference between the experimental and simulated fluences, and ηRMS, i.e., the error-weighted root mean square of the relative difference between AMS–02 experimental data and simulated differential intensities. HelMod was found to achieve a good agreement over the full set of experimental data with, typically, ΔΦ within ±2.5% and ηRMS within 5%. Usually larger or, in a few cases, much larger values for ΔΦ and ηRMS were found for the other models.

Modeling and simulation of solar PV modules based inverter in MATLAB-SIMULINK for domestic cooking

In recent days, the power extraction from renewable energy resources has become a major research area. To generate electricity from the solar energy, the Photovoltaic (PV) modules are connected either in series or parallel or series–parallel combination. The characteristics of PV modules with different environment factors are considered for simulating model in MATLAB software. In this paper, the PV modules with Maximum Power Point Tracking (MPPT) algorithm for extracting maximum power is simulated using MATLAB Simulink software. The algorithm is used to extract maximum power from the solar energy with various dynamic conditions especially irradiance and temperature levels of the PV panels. For the changing values of temperature and irradiance the voltage, current and output power of various PV modules are determined. All the results from MATLAB Simulink are verified with the theoretical calculations. The proposed model helps in understanding and analysing the various PV modules and their characteristics with changing environment conditions. In this paper 500 W of Photo Voltaic modules with AC/DC loads for domestic cooking is designed. The simulation results are compared and analysed for different types of PV modules. The results obtained from the Simulink model blocks are very similar to the actual PV modules. The simulated results obtained from MATLAB/SIMULINK which are same as reference PV modules, compatible with different types of PV module and its analysis are user-friendly.

Local interstellar spectra and solar modulation of cosmic ray electrons and positrons

Low energy cosmic rays are modulated by the solar activity when they propagation in the heliosphere, leading to ambiguities in understanding their acceleration at sources and propagation in the Milky Way. By means of the precise measurements of the e−,e+,e−+e+, and e+/(e−+e+) spectra by AMS-02 near the Earth, as well as the very low energy measurements of the e−+e+ fluxes by Voyager-1 far away from the Sun, we derive the local interstellar spectra (LIS) of e− and e+ components individually. Our method is based on a non-parametric description of the LIS of e− and e+ and a force-field solar modulation model. We then obtain the evolution of the solar modulation parameters based on the derived LIS and the monthly fluxes of cosmic ray e− and e+ measured by AMS-02. To better fit the monthly data, additional renormalization factors for e− and e+ have been multiplied to the modulated fluxes. We find that the inferred solar modulation parameters of positrons are in good agreement with that of cosmic ray nuclei, and the time evolutions of the solar modulation parameters of electrons and positrons differ after the reversal of the heliosphere magnetic field polarity, which shows clearly the charge-sign dependent modulation effect.

Update on Galactic Cosmic Ray Integral Flux Measurements in Lunar Orbit With CRaTER

AbstractWe report updated measurements of the integral fluxes of energetic protons, helium ions, and heavier ions as measured by the Cosmic Ray Telescope for the Effects of Radiation (CRaTER). CRaTER is a particle telescope that has been operating aboard the Lunar Reconnaissance Orbiter since 2009. In an earlier report, we presented the methodology used to extract linear energy transfer spectra and integral fluxes for particles with sufficient energies to fully penetrate the telescope. Results were presented for the time span from late 2009 to the end of calendar year 2014, a period that encompassed the rise of solar activity from deep solar minimum to the weak maximum of Cycle 24. Here, we update the results with data obtained from that point in time through the end of 2018, in the declining phase of Cycle 24. Fluxes obtained in the most recent data are approaching the peak levels observed in late 2009 and early 2010. The results can be used as input to models of solar modulation of galactic cosmic rays and are also relevant to human exploration of deep space.

New Very Local Interstellar Spectra for Electrons, Positrons, Protons, and Light Cosmic Ray Nuclei

Abstract The local interstellar spectra (LISs) for galactic cosmic rays (CRs) cannot be directly observed at the Earth below certain energies, because of solar modulation in the heliosphere. With Voyager 1 crossing the heliopause in 2012, in situ experimental LIS data below 100 MeV/nuc can now constrain computed galactic CR spectra. Using galactic propagation models, galactic electron, proton, and light nuclei spectra can now be computed more reliably as LISs. Using the Voyager 1 observations made beyond the heliopause, and the observations made by the PAMELA experiment in Earth orbit for the 2009 solar minimum, as experimental constraints, we simultaneously reproduced the CR electron, proton, helium, and carbon observations by implementing the GALPROP code. Below about 30 GeV/nuc solar modulation has a significant effect and a comprehensive three-dimensional (3D) numerical modulation model is used to compare the computed spectra with the observed PAMELA spectra at these energies. Subsequently the computed LISs can be compared over as wide a range of energies as possible. The simultaneous calculation of CR spectra with a single propagation model allows the LISs for positrons, boron, and oxygen to also be inferred. This implementation of the comprehensive galactic propagation model (GALPROP), alongside a sophisticated solar modulation model to compute CR spectra for comparison with both Voyager 1 and PAMELA observations over a wide energy range, allows us to present new self-consistent LISs (and expressions) for electrons, positrons, protons, helium, carbon, boron, and oxygen for the energy range of 3 MeV/nuc–100 GeV/nuc.

Dynamic electro-thermal modeling of solar cells and modules

An accurate model describing the electro-thermal behavior of solar modules, subject to varying irradiance conditions, is presented. The model relies on an enhanced version of the popular one-diode model, implementing the temperature dependence of the parameters by means of a thermal feedback network. The feedback network is built by exploiting a very effective analytical approach which reduces computational efforts and allows an automated solution. The cell-level discretization allows the description of the temperature distribution over solar cell surfaces in panels subject to mismatch events (e.g., partial shading, localized soiling, etc.), along with its time evolution. Experiments performed on a partially shaded solar string evidence good agreement with the model. In uniform condition the temperature error is less than 3 °C, while, under mismatch, the error on the maximum temperature of a cell subject to hot spot is limited to 5 °C.

New solar modulation modeling of the galactic proton flux measured by the AMS02 and PAMELA experiments

A thorough understanding of solar effects on the galactic cosmic rays is relevant both to infer the local interstellar spectrum characteristics and to investigate the dynamics of charged particles in the heliosphere. We present a newly developed numerical modulation model to study the transport of galactic protons in the heliosphere. The model was applied to the 27-day averaged galactic proton flux recently released by the PAMELA and AMS02 experiments, covering an extended time period from mid-2006 to mid-2017.

Revisit cosmic ray propagation by using 1H, 2H, 3He and 4He

The secondary-to-primary ratios are unique tools to investigate cosmic ray propagation mechanisms. In this work, we use the latest data of deuteron-to-helium 4 ratio and helium 3-to-helium 4 ratio measured by PAMELA combined with other Z≤2 primary fluxes measured by PAMELA and Voyager-1, to constrain the cosmic ray acceleration and propagation models. The analysis is performed by interfacing statistical tools with the GALPROP propagation package. To better fit both the modulated and unmodulated low energy cosmic ray data, we find that a time-, charge- and rigidity-dependent solar modulation model is better than the force-field approximation. Among all the studied cosmic ray propagation models, the diffusion–reacceleration–convection model is strongly supported by the derived Bayesian evidence. The robustness of the estimated diffusion slope δ is cross-checked by another low-mass secondary-to-primary ratio, i.e. the antiproton-to-proton ratio. It is shown that the diffusion–reacceleration–convection model can reconcile well with the high energy antiproton-to-proton ratio. This indicates that the estimated value of δ is reliable. The well constraint δ from the “best” model is found to be close to 1/3, inferring a Kolmogorov-type interstellar magnetic turbulence.

Evidence for a Time Lag in Solar Modulation of Galactic Cosmic Rays

Abstract The solar modulation effect of cosmic rays in the heliosphere is an energy-, time-, and particle-dependent phenomenon that arises from a combination of basic particle transport processes such as diffusion, convection, adiabatic cooling, and drift motion. Making use of a large collection of time-resolved cosmic-ray data from recent space missions, we construct a simple predictive model of solar modulation that depends on direct solar-physics inputs: the number of solar sunspots and the tilt angle of the heliospheric current sheet. Under this framework, we present calculations of cosmic-ray proton spectra, positron/electron and antiproton/proton ratios, and their time dependence in connection with the evolving solar activity. We report evidence for a time lag months, between solar-activity data and cosmic-ray flux measurements in space, which reflects the dynamics of the formation of the modulation region. This result enables us to forecast the cosmic-ray flux near Earth well in advance by monitoring solar activity.

Transient and Steady-State Response of a Fractional-Order Dynamic PV Model Under Different Loads

In this paper, a fractional-order dynamic model of the photovoltaic (PV) solar module is introduced. Dynamic modeling of PV solar modules is useful when used in switching circuits and grid-connected situations. The dynamic elements of the proposed model are a fractional-order inductor and capacitor of two independent orders which allow for two extra degrees of freedom over the conventional dynamic model. The step response and transfer function of the load current are investigated for different orders under resistive and supercapacitor loading conditions. Closed-form expressions for the time response of the load current at equal orders of capacitor and inductor are derived. Stability analysis of the load current transfer function is carried out for different orders and loading conditions. The regions for pure real and pure imaginary input admittance scenarios are calculated numerically for both resistive and supercapacitor load cases. It is found that the order of the inductor has a dominant effect on the responses. As a proof of concept, the model is fitted to experimental data to show its flexibility in regenerating the actual response. The fitted fractional-order model response is compared to optimized integer-order ones from literature showing noticeable improvement.

A predictive analytic model for the solar modulation of cosmic rays

An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time and charge-dependent effects on the spectrum and intensity of low energy ($\lsim$ 10 GeV) cosmic rays reaching Earth. Previous analytic treatments of solar modulation have utilized the force-field approximation, in which a simple potential is adopted whose amplitude is selected to best fit the cosmic-ray data taken over a given period of time. Making use of recently available cosmic-ray data from the Voyager 1 spacecraft, along with measurements of the heliospheric magnetic field and solar wind, we construct a time, charge and rigidity-dependent model of solar modulation that can be directly compared to data from a variety of cosmic-ray experiments. We provide a simple analytic formula that can be easily utilized in a variety of applications, allowing us to better predict the effects of solar modulation and reduce the number of free parameters involved in cosmic ray propagation models.